<!-- <html>
    <head>
        <title>这是网页标题</title>
    </head>
    <body>
        hello world! This is my first htmlcode
    </body>
</html>  -->

<!DOCTYPE html>
<html lang="en"> <!--html文本是英语-->
<head>
    <meta charset="UTF-8">  <!--告诉浏览器-->
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    
</body>
</html>